server.properties with Java System Properties

[aderosso]

How do I reference Java system properties in the server.properties file?

I'm passing in values to the JVM using the -D flag, ie: -Ddb.host=localhost

I'm trying to configure a database connection, here's the relevant block from my server.properties:

sql.defaultDatabase:Mysql
sql.defaultDatabase.type:mysql
sql.defaultDatabase.interface.type:dataSource
sql.defaultDatabase.driver:org.mariadb.jdbc.MariaDbDataSource
sql.defaultDatabase.driver.serverName:${db.host}
sql.defaultDatabase.driver.portNumber:3306
sql.defaultDatabase.driver.databaseName:${db.name}
sql.defaultDatabase.driver.user:${db.user}
sql.defaultDatabase.driver.password:${db.password}

I've verified that the referenced properties are available from System.getProperty(). I know I can use a listener before the SC framework starts and I can add them manually to the Config, but I was curious if something like this is already supported in server.properties directly.

Right now I get the error:

java.lang.Exception: variable expansion failed for variable: db.host

[Isomorphic]

Yes, you can do this as follows:

 -Disc_config:db.host=localhost

Then your ${db.host} reference in server.properties will resolve to 'localhost'

As of 12.1 (not yet released as of the time of this of this writing), you'll be able do do this:

sql.defaultDatabase.driver.serverName: $SYS{db.host}

And then, -Ddb.host=localhost will be picked up.

One note on this: command line properties can observed from the process listing on most operating systems, so be careful with passing sensitive data like passwords in this manners. You can use environment variables:

sql.defaultDatabase.driver.serverName: $ENV{ENV_VAR_NAME}

[aderosso]

Exactly what I was looking for, thank you!